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Formula: AgAuTe4
Telluride
Crystal System: Monoclinic
Specific gravity: 8.16 measured, 8.161 calculated
Hardness: 1½ to 2
Streak: Grey
Colour: Silver-grey, whitish
Solubility: Insoluble in water, hydrochloric and sulphuric acid; slightly soluble in nitric acid
Common impurities: Sb,Pb,Cu,Ni
Environments:
Sylvanite occurs most commonly in low-temperature hydrothermal veins, but also in moderate and high temperature deposits;
it is usually among the last minerals formed
(Webmin).
Associated minerals include gold, calaverite,
krennerite, altaite,
hessite, petzite,
acanthite, pyrite,
galena, sphalerite,
chalcopyrite, quartz,
chalcedony and fluorite
(HOM).
Localities
At Cobar, New South Wales, Australia, sylvanite is a minor ore mineral
(AJM 11.2.69)
At the Kalgoorlie district, Western Australia, good specimens of sylvanite with gold have
been found. Associated minerals include calaverite,
hessite, petzite,
coloradoite, chalcopyrite,
tetrahedrite, quartz,
apatite and tourmaline
(R&M 96.3.206).
At the Ida May deposit, Bridge River area, Lillooet Mining Division, British Columbia, Canada, sylvanite occurs with native
gold and stibnite
(R&M 96.3.205).
In an occurrence at Fortune Lake, Arntfield, Rouyn-Noranda TE, Abitibi-Témiscamingue, Quebec, Canada, spectacular showings of
sylvanite, gold and petzite were found in
quartz-ankerite veins
(R&M 96.3.205).
At the Buffalo Hump claims on Mount Stevens, Yukon Territory, Canada, sylvanite is found with
galena and gold
(R&M 96.3.205).
At Gold Hill, Wheaton River District, Whitehorse mining district, Yukon, Canada, sylvanite occurs with
hessite, petzite and
gold
(R&M 96.3.206).
At the Emperor Mine, Vatukoula, Vatukoula Gold Field, Viti Levu, Fiji, fine sharply developed, deeply striated lustrous crystals of
sylvanite to 3.5 cm long are associated with quartz,
gold, petzite,
coloradoite, krennerite,
empressite, nagyágite,
hessite, melonite, native
tellurium, arsenopyrite and
stibnite
(R&M 96.3.206).
At the type locality, Baia de Arieș, Alba, Romania, sylvanite is associated with gold
(R&M 96.3.206).
Sylvanite from Baia de Arieș - Image
At the Sugarman and Nigger Mine, Browns Flat, Columbia District, East Belt, Tuolumne county, California, USA, exceptional
gold specimens with sylvanite and petzite have
been found
(R&M 96.3.205).
At Boulder county, Colorado, USA, sylvanite occurs with native gold in many localities
(R&M 96.3.205).
At Cripple Creek, Teller county, Colorado, USA, sylvanite is found associated with calaverite and
krennerite, and sometimes pseudomorphed
by gold
(MinRec 36.2.179).
At the Cresson Mine, Eclipse Gulch, Cripple Creek Mining District, Teller county, Colorado, USA, in a vug 12 x 6 x 4 metres in size,
discovered in 1914, well crystallised calaverite, sylvanite and flaky native
gold associated with celestine were found
(R&M 96.3.205).
At the Trojan District, Lawrence county, South Dakota, USA, fine sylvanite specimens have been found with minor
gold
(R&M 96.3.205).
At the Tintic Mining District, Utah, USA, sylvanite occurs mostly as solid metallic masses in
gold ores from the eastern part of the district, although not in great
abundance. It has been reported from the Trixie, Tintic Standard, Eureka Standard and North Star mines. A specimen
with a vein of massive sylvanite in quartz associated with
pyrite has been found
(MinRec 55.2.223).
Sylvanite from Tintic - Image
At the Beecher Mine, Rockcut, Orient District, Stevens county, Washington, USA, sylvanite is intimately associated with
gold
(R&M 96.3.205).
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